Electrically driven hospital chair



ELECTRICALLY DRIVEN HOSPITAL CHAIR 1 Filed June 9, 1947 4 Sheets-Sheet l ,JZ Q

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I/Vaxweg Feb. 19, 1952 STEVEN ELECTRICALLY DRIVEN HOSPITAL CHAIR 4 SheetsSheet 2 Filed June 9, 1947 Z V yup ya 2 o wfi W Z 6 2 M A Z j a w X L a @fiy Feb. 19, G E I ELECTRICALLY DRIVEN HOSPITAL CHAIR Filed June 9, 1947 .4 she ts-sheet 4 Patented Feb. 19, 1952 STATES PATENT OFFICE Glenn-A. Steven, Kansas City, Kans., assignor to The -Electro- Gli'de Company,iInc., Kansas' City, Kans.,=a corporation of Kansas Application June 9, 1947,.SeriaLNo. 753,544

17 Claims. 1

.This invention relates tonew-and'useful improvements in .a 'hospital .chair, and "has particular reference to hospital chairs :of the motor driven type.

The principal object of the present invention is the provision of a motor driven hospital chair wherein the functions of starting, stopping, braking, reversing, steering, and speedregulation are accomplished bygthe manipulation of a single gcontrol lever.

Another object-is the provision of an electrically driven hospital chair wherein the operation of both electrical and mechanical control devices is controlled by a single control lever.

Another object is the provision of a hospital chair which is electrically driven and mechanically steered, the driving and steering means being both operated by a single control lever.

Another object is the provision, in a hospital chair of the class described, of "brakes adapted to be applied automatically whenever the rider releases the control lever.

Sti11 another object is the provision of a hospital chair supported-bytwo front wheels and a :-rear tiller wheel, said tiller wheel being oscillata- :ble to steer said chair.

Other objects are simplicity and .economy of construction, ease and convenience of operation, :and adaptability for use *by 'very seriously disabled invalids.

With :these objects in'view, as well as other objects which will appear during the course of the specification, reference will :now "be had to the drawings, wherein:

Figure l is-aside elevation of :ahospital chair "embodying the present invention.

Fig. 2 is-a plan view of the chair.

Fig. 3 is .-a horizontal section taken on line III-III of Figure .1, with some parts :brokenaway and others left in elevation.

Fig. 4 is an enlarged fragmentary vertical section taken on line I-V-IV of Figure .3, with parts left-in elevation.

Fig. 5 is a fragmentary vertical :section taken on line V-VofFigure 3, with the batterycharg- .er removed.

metal stock.

Fig.11 is .a sectional view .taken on line XI-XI ;of Figure 8.

Fig.12is a schematic wiring diagram of the chair, also showing schematically the mechanical operation of the motor brakes.

Like reference numerals apply to similar parts throughout the several views, and the numeral I4 applies to the main frame constructed in the showing contained in the drawings ofv tubular Said frame includes a substantially rectangular lower'frame I6 having a planar foot rest I8 fixed in the forward end thereof and being shaped to present an outwardly extending arcuate curve 20 at the rearward end thereof, said curve permitting the oscillatory movement of tiller wheel 22. A substantially semi-circular frame'member '24 is fixed to each side of lower frame [6 adjacent the forward end thereof, and extends upwardly-to encircle a main wheel 26. Lower frame It is cut outbetween the lower ends offrame member 24 to permit said wheelsto'be set inwardly. The gaps caused by thus cutting out the lower frame are closed by rigidly connecting angle irons "28 along the inner edges of said'irame as shownin Figures 4 and'5.

A substantially U-shaped horizontal upper frame 30 is rigidly fixed at its forward ends to semi-circular members 24, and at its rearward end supports a bearing member 32 adapted to :carry vertical shaft '34 for oscillation therein. Said shaft carries a downwardly extending bifurcated member 36 between the arms of which *till'er wheel .22 is carried for rotation. Bearing 132 is vertically above the center of curvature of arc 20 of lower frame IS. A brace member 31 rigidly connects the upper and lower frames at the rearward ends thereof.

- "Bars 38 rigidly fastened to the inner surface of semi-circular members 24, as shown in Figure 5, 'arein substantial horizontal alignment with upper frame 30. An upwardly extending back support .40 is rigidly attached to each side of upperframe 3!! intermediate its ends, and a cross bar 42 extends between the upper ends of said supports. Chair back 44 is fastened to said .cross bar. .A cushioned chair seat 46 is sup- *portedpn members extending horizontally'between bars 38.

.An .arm rest support 50 is rigidlyattached at eoneend to each of .back supports 4.0,and at its opposite end to semi-circular member 24. A padcled arm .rest .52 is secured .to each of supports '55! by means of brackets 54.

Thespace between .upper frame 30 and lower frame It is substantially enclosed by sidepanels 56,, a rear-panel i58spacedforward1y from tiller wheel 22, and a front panel 66 disposed beneath the forward edge of chair seat 46, said panels being supported by said upper and lower frames. A shelf 62, as shown in Figure 5, extends across the bottom of said enclosure adjacent the rearward end thereof, and serves as a support for storage battery 64, and battery charger 66. A removable cover 68, as shown in Figure 5, extends across upper frame 36 adjacent rear panel 58, and provides access to the battery and charger. A fender 88 is fixed to each side panel 56, and extends outwardly above the adjacent main wheel 26.

A horizontally extending lever arm I6 is rigidly fixed to bifurcated member 36 carrying tiller wheel 22. A connecting rod I2 is pivotally connected to the free end of said lever, extends forwardly through a hole I4 provided therefor in rear panel 58, and is pivotally connected at its forward end to one arm of a bell-crank lever I6. Said lever is pivotally mounted at I8 to a plate 86 rigidly fixed between the upper and lower frames at the right side thereof. A connecting rod 82 is pivotally connected to the other arm of bell-crank lever I6, extends upwardly through cover 68, and is pivotally connected at its upper end to a crank arm 84 rigidly fixed to the rearward end of a shaft 86, as best shown in Figure 6. Said shaft extends forwardly through right arm rest support 56, and is adapted to be oscillatably rotated therein. Control switch housing 96 is rigidly fixed to the forwardly extended end of said shaft. Thus, whenever said switch housing is manually oscillated to turn shaft 86, crank arm 84 will operate connecting rod 82, bell-crank I6, connectin rod I2, and lever arm I6 to turn tiller wheel 22.

Each of main wheels 26 is mounted on a shaft 92 .iournaled in a bearing 94 which extends through a ho e 96 in side panel 56 and is carried by a gear reduction box 98. Said gear box is ri id y fixed to a pair of bars I 66 extending vertically between and fixed at their opposite ends to an le iron 28 and horizontal bars 38.

A gear I 2 is ri idly fixed to the inner end of each shaft 92 within ear box 88, and is adapted to mesh with a gear I64 fixed on an intermediate sha t I 66 ,iournaled in said gear box as shown in Figure 4 A larger gear I68 is also fixed to shaft I6 and meshes with a pinion I I6 fixed on shaft II2 of motor H4. Said motor is rigidly fixed to gear box 98. It will be noted that since the above named gears are substantially in line, motor I I 4, and motor II 5 driving the other wheel 26, are offset from wheel shafts 62. In the showing made, this offset is upward for one wheel and rearward for the other wheel, thus avoiding interference between the motors.

Motors II 4 and H5 are of a standard type having brakes incorporated therein. Referring to the schematic showing in Figure 12, it will be seen that there is a friction disc H6 fixed to and rotatable with motor shaft I I2 within the motor housing. Another friction disc H8 secured against rotation but movable longitudinally to the motor shaft, is normally urged against rotatable disc H6 by springs I26, thus applying a braking force to the'rotation of shaft 92. A solenoid I22 is adapted to draw disc H8 out of contact with disc H6 against the pressure of springs I26 whenever electric current is supplied thereto.

Referring to Figure 3, an electrical connector fixture I24 is fixed in rear panel 58. Any suitable source of electric current may be conveniently connected therein to supply current to battery charger 66 through wires contained in cable I26. To front panel 66 are fixed a power switch I28 and a box I36 containing the necessary relays and resistors as hereinafter described. The numeral I32 applies to conduits containing wires for supplying current from battery 64 to motors H4 and H5. Referring to Figure 5, it will be seen that a branch I34 of said conduit passes outwardly through a hole I36 provided in front panel 60 and enters an arm rest support 56 adjacent the point said support is fixed to semi-circular frame member 24. Said conduit extends upwardly through said support and emerges therefrom at a point spaced rearwardly from control switch housing 96, as shown in Figure 1. The conduit then extends forwardly, is fixed to said switch housing adjacent shaft 86 by a bracket I38, and thence enters the switch housing through hole I46, as shown in Figure 9. This arrangement of conduit I34 permits the oscillation of switch housing 96 to steer the chair as previously described without undue twisting of the conduit.

Referring to Figures 6 to 12, it will be seen that housing 96 contains a compound switch I42. Said housing is substantially fiat, and has an oscillatable shaft I44 extending substantially therethrough adjacent the lower edge thereof and carried in bearing portions I46 thereof. A hand lever I48 is fixed to the extended end of said shaft outside of the housing by means of a collar I56. Said lever is constantly urged to ward a central or neutral position by means of a leaf spring I52, and the oscillatory movement of said handle is limited by a pair of stops I54 secured to housing 96 adjacent the upper edge thereof.

A contact knife I56 is rigidly mounted on shaft I44 within housing 86, and is adapted to move coextensively with hand lever I48. The upper end portion of said knife contact is adapted to move between and in sliding contact with a pair of parallel spaced apart bars I58, said barsbeing rigidly carried by and electrically connected to housing 86. A plate I66 of insulating material is fixed rigidly in housing 96 parallel to the; arc of movement of knife contact I56. A series of spring contacts, numbered I62, I64, I66 and I66,- are fixed to said insulator plate along each side of contact knife I56 by means of bolts I'I6, as best shown in Figure 8, so that they will be contacted by knife I56 whenever it is reciprocated as described. Corresponding contacts of each series are spaced equally from the central position of knife I56, and the contacts of each series are spaced apart from said central position at grad-- uated distances so that knife I56 will Contact them in succession, not simultaneously. Corre-' sponding contacts of each series are connected by a series of bars I'I2 extending between bolts I16 on the opposite side of insulator plate I66, as best shown in Figure 9. An additional spring contact H4 is provided at one side of knife I56, the knife contacting said spring contact only when the knife is moved in one direction. This; contact provides for reversal of the motors.

Referring to Figure 12, it will be seen that whenever a suitable electric current is supplied. to connector I24 as described. current will be sup-- plied through "wires I16 and I18 to battery charger Charging current passes from said charger" through wire I86, and through wire I82, wire Hi l,v

and wire I86 to storage battery 64. As long as knife contact I56 remains in a neutral position,

lay Z34, Wires 2'44 and 245,

accepts 5 no :current will :flow, since switch A42 and ;relays I88, I90 andzrl 92 areopen. Atvthisytime'thebr-akes also are applied, sincersolenoids I 22 are ZnotzeIlergized. When the occupant :of :the chair desires to moveforwardly, he moves hand lever I48 forwardly, thus moving knife I56 forwardly, or to the left :as viewed in Figure 112. The knife first touches contact I62, and current then flows from battery 64 through wire I94, contact I62, knife I56, conductor I96, and conductor I98 to brake solenoids I22, and thence through wire I86,,1a-nd wire 269 to battery .64. The solenoidsthus energized, will separate friction discs I I6 and H3 as previously described to release the brakes.

Since leaf spring 152 will return knife I56 to neutral whenever hand lever I48 is released, and since solenoids I22 will then becomerde-energized andcause thebrakes to be reappliedan important safety precaution is thereby accomplished. *In

the embodiment shown, the frame 1'4 serves as --conductors I96 and I98, since knife I56 and sole- :noids .I 22 are grounded to said frame.

Knife I56 next touches contact I168, current .thenflowing from the battery through wire I 94, contact I62, knife I56, contact I68, wire 202, the

coil of relay I92, wire 265, wire I82, and wire 'I I84 to common return 186. Relay I92 is thus closed, and current flows from wire I 94 through wire 286, wire i208, relay I92, wire 2"), resistor 2l2, resistor .2I4, common feed wire 2J6, wire 21.8, armature windings 220 of motor I I5, wire 222, power switch I 28, wire I224, armature windings 226 of motor 4, wire228, and wire 23!) to common return I96. The armature windings are thus connected in series, "and consequently each armature isL-subjected to about one-halfof the battery voltage not consumed by resistors 2I2 and 2I4. If switch I28 is thrown to the position opposite from that shown .in Figure 12, current flows from common feed wire2l 6 through wire 2 I8, armature windings-226, wire 222, switch I28, and wire 230 to comm'on'return I 86, and also from common feed wire 2I6 through switch I28, wire 224, armature windings 226, and wire 230 to common return I 86. The armature windings of the two motors are thus connected in parallel, and each is subjected to the full battery voltage not consumed by resistors 2 I2 and 2 I4. The speed of the motors and the chair is thus increased. It is contemplated that switch I28 be used only when substantial speed changes aredesired, for example to use the series connected armatures for indoor use and the parallel connected armatures for outdoor use.

The field windings of the motors are energized from common feed line 2.I6 through wire 232 and a double pole-double throw relay 234 normally having the position shown in Figure .12, With the relay in this position, current flows :from wire 232 through the relay, wire 236, wire 236, and 240 to field windings 242, and thence'through wires 244 and 246, relay 234 and Wire 248 to common return I86. Motors II 4 and H5 will then turn Wheels 26 through the reduction gearing above described to move the chair forwardly. "However, if knife I56 is moved rearwardly, ,or to the right as viewed in Figure -1 2, it-will touch the reversing contact I14 before it touches any of the contacts I64, I66 or I68. Current will'then flow from the battery through wire I94, contact I62, knife I56, contact I14, wire 256, through thecoil of relay 234, thence through wires 252 and 248 to common return I86. With-relay 234 thus actuated, the field current of the motors will flow from common feed wire 2 I6 through wire 2-32, re-

field windings 242,

wires'238 and 234, wire 236, relay 234, and wire The direction of be caused to turn in a reverse direction.

Whenever knife 156 is moved far enough in either direction to touch contact I66, battery current will flow through wire I94, contact I62, knife I56, contact I66, wire 254, the coil of relay I90, wire 256, wire I82, and wire I84 to common return I86. Relay I98 then being closed, current flows through wire I94, wire 2B6, wire 258, relay I90, wire 266, and resistor 2I4 to common feed wire :2.I6, and thence to motors I I4 and H5 as previouslydescribed. Since only one resistor is then in the circuit, a higher voltage is supplied to said motors and a higher speed results.

Whenever knife I56 is moved still farther in either direction and touches a contact I64, current will flow from the battery through wire I94, contact I62, knife I56, contact I64, wire 262, the coil of .relay I88, wire I82, and Wire I 84 to common .return I86. Since relay I88 is then closed, battery current flows through wire 266, relay I88, and wire 264 to common feed wire 2 I 6, and thence to the motor windings as previously described. Since neither of the resistors 2I2 or 2I4 are then in the circuit, substantially the full battery voltage will be applied to the motor windings, and a still out departing from the spirit of the invention.

Thus it appears that ahospital chair has been produced wherein all control functions, both mechanical and electrical, have been concentrated in a single manually operable hand lever I48. The functions include starting, stopping,

-b1'aking,.reversing, and speed control. The operator of the chair grasps hand lever I48. .By moving it forwardly, the brakes are released and the chair driven forwardly, speed being determined by the Rearward movement of handle I 48 will cause the chair to be driven rearw-ardly, with the same speed conamount the hand lever is .moved.

trol. Whenever the hand lever is moved to its central or neutral position, the brakes are applied automatically. .As a safety measure, spring I52 isprovided to return hand lever I48 to neutral whenever the occupant releases said. hand lever due to fainting or other sudden disability. By oscillating thehand lever .to the right or left, the chair may be steered as desired.

While ,hand lever I48 is shown disposed conveniently to the righthand of the chairs occupant, it is apparent that it could be placed in position tobe operated by either hand, or by the .feet. without departing from the invention. Its

adaptability ,to .invalids .of many classes is further increased by the face that operation of the .chair requires no .finger action, and only a very limited degree of movement.

These .and many other minor changes of construction and arrangement of parts could manifestly be made without departing from the spirit of the invention, anditis therefore desired to be .limited only by the scope of the appended claims.

erable lever having .a neutral ,or inoperative position carried by said chair and operable by movement away from its neutral position to close said switches to operate said motors, mechanical brakes normall applied to said motors by spring pressure, electrical means independent from said motor circuit to release said brakes, said lever being operable during its initial movement to actuate said last named electrical means to release said brakes before said motors are started.

2. A hospital chair having wheels and electric motors for driving said wheels, means controllable by electric switches for supplying operating current to said motors, a manually operable lever having a neutral or inoperative position carried by said chair and operable by movement away from its neutral position to close said switches to operate said motors, mechanical brakes normally applied to said motors by spring pressure, electrical means independent from said motor circuit to release said brakes, said lever being operable during its initial movement to actuate said last named electrical means to release said brakes before said motors are started, and resilient means urging said lever toward its neutral position.

3. A hospital chair having wheels and electric motors for driving said wheels, means controllable by electric switches for supplying operating current to said motors, a universally oscillatable lever having a neutral or inoperative position carried by said chair and operable by movement in a first plane from its neutral position to close said switches to operate said motors, mechanical means operable by the pivotal movement oi. said lever in a plane transverse to said first plane for steering said vehicle, mechanical brakes normally applied to said motors by spring pressure, electrical means controllable by an electrical switch to release said brakes, said lever being operable during its initial movement in said first plane to close said brake releasing switch before said motor switches are closed, and resilient means urging said lever toward its neutral position in said first plane.

4. In a hospital chair having two drive wheels and an electric motor for driving each of said wheels, an electric circuit for supplying current to said motors and including electric switches, a lever carried by said chair for movement from a neutral position to an operative position whereby said switches are closed to energize said motors, brakes mechanically applied to each of said motors by spring pressure, an electric circuit indedependent of said motor circuit and including means for releasing said brakes, an electric switch for closing said brake circuit to release said brakes, said switch being operable by said lever at a position intermediate its neutral position and its motor-energizing position, and resilient means urging said lever toward its neutral position.

5. In a hospital chair having an electric motor for turning each of the drive wheels thereof and a storage battery for supplying current to said motors, a plurality of series-connected resistors in the circuit between said battery and said motors, a brake normally applied to each of said motors by spring pressure, an electric circuit independent of said motor circuit and including means for releasing said brakes, a control lever carried movably by said chair, said lever having a neutral position, electrical switching means operable by the movement of said lever away from its neutral position to successively close said brake circuit to release said brakes, close said motor circuit to energize said motors, and successively remove said resistors from the motor circuit, and resilient means urging said lever toward its neutral position.

6. In a hospital chair having an electric motor for turning each of the drive wheels thereof and a storage battery for supplying current to said motors, a plurality of series-connected resistors in the circuit between said battery and said motors, a brake normally applied to each of said motors by spring pressure, an electric circuit independent of said motor circuit and includin means for releasing said brakes, a control lever carried movably by said chair, said lever having a neutral position, electrical switching means operable by the movement of said lever in one direction from its neutral position to successively close said brake circuit to release said brakes, close said motor circuit to turn said motors in one direction, and successively remove said resistors from the motor circuit, said switching means being operable by the movement of said lever in the opposite direction from its neutral position to successively close said brake circuit, close said motor circuit to turn said motors in a reverse direction, and successively remove said resistors from said motor circuit, and resilient means urging said lever toward its neutral position.

'7. In a hospital chair having an electrical motor for turning each of the drive wheels thereof,

a brake normally applied to each of said motors by spring pressure, an electrical circuit for furnishing current to said motors, a plurality of series-connected resistors in said motor circuit, an

5 independent electrical circuit including means for releasing said brakes, an oscillatable ground-engaging tiller wheel for steering said chair, a housing carried for rotary oscillation by said chair and operable by said oscillation to control said 4 tiller wheel, a lever carried by said housing by means of which said housing may be turned to control said tiller wheel, said lever being manually oscillatable relative to said housing on an axis at right angles to the axis of said housing, electrical switching means carried in said housing and operable by the oscillation of said lever to successively close said brake-releasing circuit, close said motor circuit, and successively remove said resistors from the motor circuit, and resilient means urging said lever to a position wherein both the brake-releasing and motor circuits are opened.

GLENN A. STEVEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 581,557 Huff Apr. 27, 1897 653,169 Coleman July 3, 1900 659,078 Lieb Oct. 2, 1900 55 671,214 Judd Apr. 2, 1901 994,080 Henderson May 30, 1911 1,429,213 Gladish Sept. 12, 1922 1,540,170 Frick June 2, 1925 2,059,244 Kiekhaefer Nov. 3, 1936 2,348,053 Bowker May 2, 1944 FOREIGN PATENTS Number Country Date 326,880 Italy June 25, 1935 '5 501,007 Great Britain Feb. 13, 1939 

